The field experiment was conducted to evaluate the economic feasibility of LPLC drip system for broccoli and tomato with four treatments. Daily drip irrigation maintained soil moisture near field capacity in 30 and 60 cm depth of soil profile. The seasonal water requirement was found to be 20.08, 19.68, 18.61 and 21.06 cm respectively for treatments T1, T2, T3 and T4 and corresponding WUE are 1.46, 2.85, 3.41 and 0.82 t/ha-cm. The mean yield of fruit of broccoli and tomato in treatment T1 (1.01 kg/plant and 29.27 t/ha) followed by T4 (0.60 kg/plant and 17.33 t/ha) and T3 (2.19 kg/plant and 63.46 t/ha) followed by T2 (1.93 kg/plant and 56.03 t/ha) respectively. The developed system has pay back period of one season only, benefit to cost (B/C) ratio ranges from 1.52 to 5.31 without subsidy and 4.28 to 8.30 with subsidy. Thus, appropriate, affordable, accessible, low operation and maintenance cost, users friendly LPLC drip irrigation system is better alternative for small land holders.

INTRODUCTION OF LPLC drip irrigation system

In world and specially in India, 70 per cent of farming
population consists of small and marginal farmers cultivating land less than 1
hectare in size, average size of which decreases by half every 15 years due to
the rapid population growth. Today nearly 60 per cent of the farmers belong to
marginal category with an average of 0.4 ha land. Agriculture in India is
mainly rainfed and majority of the farmers have little access to alternate
source of irrigation. These poor farmers are still dependent on the vagaries of
the monsoons to sustain their livelihoods. Thus, no availability of affordable
and dependable irrigation systems is a major factor behind ever-increasing
number of farmers being drawn into the poverty spell1

Drip irrigation system offers unique agronomical, agro technical and economical advantages for efficient use of valuable water resources. However, the initial cost of drip irrigation limits its scope for large scale adoptions. The Indian government has sought to promote pressurized irrigation technologies primarily by subsidizing the cost of equipment. Despite subsidies of as much as 75 per cent of total cost of equipment, the rate of adoption is very slow and uneven. The Rajasthan State Government approved rate of 70 per cent subsidy ranging from Rs 19206 to Rs 163400 per hectare for drip irrigation.

Drip irrigation tradle pump

The present drip irrigation system technologies are expensive and fit for use only in large fields. International Development Enterprises-India (IDEI) embarked upon the innovative adaptations of low cost drip irrigation systems catering to the needs of the small farmers, bringing in more flexibility, simplicity and affordability. IDEI promoted drip kits cost almost 80 per cent cheaper than the conventional kits and thus bring about a shift from subsistence farming to higher value production farming doubling the income of the poor farmers and greatly enhancing household food security. The drip irrigation technology and treadle pump technology frees the farmer from the limitations of rainfed farming, enabling him to grow wide variety of crops, cultivate all the year round with higher cropping intensity and priority farming. Good irrigation technologies and agricultural practices coupled with enhanced participation of the poor in the markets is the key to income generation. IDEI promotes affordable drip irrigation technologies (ADITI) in the form of packaged and ready-to-use kits such as bucket kit, drum kit, and customized systems which are used by farmers for growing both horticulture and cash crops. Till date 85,000 small and marginal farmers have been successfully adopted these kits. It has working head 0.5-3 m with 73-84 per cent distribution uniformity2. Higher head in Krishak Bandhu (KB) drip system with increasing height of source is difficult to maintain and costly also. However, no low cost drip irrigation system has been designed more than 3 m head.

There
is a need to develop an efficient suitable low pressure low cost (LPLC) drip
irrigation system having working head of more than 3 m with higher distribution
uniformity, constructed with locally available materials that would be
adoptable and affordable for small land holders.

It was surveyed3 on existing treadle pumps; low-cost drip
irrigation and water storage systems reported that 550 million of the current
1.1 billion people earning less than $1-a-day earn a living from agriculture in
developing countries. A revolution in water control is needed to develop and
mass-disseminate new, affordable, small-plot irrigation technologies. A
revolution in agriculture is required to enable smallholders to produce
high-value, marketable, labor-intensive cash crops. A revolution in markets is
needed to open access to markets for the crops they produce and the inputs they
need. Finally, a revolution in design, based on the ruthless pursuit of affordability,
is needed to harness shallow groundwater.

Scientific water management, farm practices and drip system
should be adopted wherever feasible. The development of an efficient, reliable
and low cost drip system that fits the needs of small farmers in developing
countries has long been recognized as a critical need. The objectives of
present investigation were to develop a low cost efficient suitable drip,
fabricated with materials available in local market, which is adoptable and
affordable for small land holders.

Drip irrigation system offers unique agronomical, agro technical and economical advantages for efficient use of valuable water resources. However, the initial cost of drip irrigation limits its scope for large scale adoptions. The Indian government has sought to promote pressurized irrigation technologies primarily by subsidizing the cost of equipment. Despite subsidies of as much as 75 per cent of total cost of equipment, the rate of adoption is very slow and uneven. The Rajasthan State Government approved rate of 70 per cent subsidy ranging from Rs 19206 to Rs 163400 per hectare for drip irrigation.

The present drip irrigation technologies are expensive and
fit for use only in large fields. International Development Enterprises-India
(IDEI) embarked upon the innovative adaptations of low cost drip irrigation
systems catering to the needs of the small farmers, bringing in more
flexibility, simplicity and affordability. IDEI promoted drip kits cost almost
80 per cent cheaper than the conventional kits and thus bring about a shift
from subsistence farming to higher value production farming doubling the income
of the poor farmers and greatly enhancing household food security. The drip
irrigation technology and treadle pump technology frees the farmer from the
limitations of rainfed farming, enabling him to grow wide variety of crops,
cultivate all the year round with higher cropping intensity and priority
farming. Good irrigation technologies and agricultural practices coupled with
enhanced participation of the poor in the markets is the key to income
generation. IDEI promotes affordable drip irrigation technologies (ADITI) in
the form of packaged and ready-to-use kits such as bucket kit, drum kit, and
customized systems which are used by farmers for growing both horticulture and
cash crops. Till date 85,000 small and marginal farmers have been successfully
adopted these kits. It has working head 0.5-3 m with 73-84 per cent
distribution uniformity2. Higher head in Krishak Bandhu (KB) drip system with
increasing height of source is difficult to maintain and costly also. However,
no low cost drip irrigation system has been designed more than 3 m head.

There is a need to develop an efficient suitable low pressure low cost (LPLC) drip irrigation system having working head of more than 3 m with higher distribution uniformity, constructed with locally available materials that would be adoptable and affordable for small land holders.

It was surveyed3 on existing treadle pumps; low-cost drip
irrigation and water storage systems reported that 550 million of the current
1.1 billion people earning less than $1-a-day earn a living from agriculture in
developing countries. A revolution in water control is needed to develop and
mass-disseminate new, affordable, small-plot irrigation technologies. A
revolution in agriculture is required to enable smallholders to produce
high-value, marketable, labor-intensive cash crops. A revolution in markets is
needed to open access to markets for the crops they produce and the inputs they
need. Finally, a revolution in design, based on the ruthless pursuit of
affordability, is needed to harness shallow groundwater.

Treadle pump for drip irrigation system

Scientific water management, farm practices and drip system should be adopted wherever feasible. The development of an efficient, reliable and low cost drip system that fits the needs of small farmers in developing countries has long been recognized as a critical need. The objectives of present investigation were to develop a low cost efficient suitable drip, fabricated with materials available in local market, which is adoptable and affordable for small land holders.

MATERIALS USED IN DRIP IRRIGATION AND METHODS FOR DRIP IRRIGATION system

The field experiment was conducted in 2008-09 at
Horticulture Farm, Rajasthan College of Agriculture, Udaipur. Krishak Bandhu (KB)
drip irrigation system consisted of KB pressure treadle pump, KB pipes (submain
and laterals), microtubes and its necessary accessories with pressure drum (200
l) and medical infusion set here after referred as medi-emitters were used. MS
Drum was used as buffer pressure tank. The capacity of pressure treadle pump
varies from 3000 to 5000 l/h with delivery head up to 13 m. One man can operate
treadle pump for one hour continuously.

The irrigated field (25 m x 25 m) was
divided into four subplots (12.5 m x 12.5 m) and pressure drum (source) was
kept in the centre of the field. System was designed for tomato (Lycopersicon
esculentum Mill) cv. Dev variety and broccoli (Brassica olreacea L. var.
italica) cv. Aishwarya (F1 – Hybrid) using microtubes (0.9 mm ID) and
medi-emitters (3 mm ID) on both vegetable crops with plant to plant spacing of
0.45 m, row to row spacing of 0.60 m and operating head of 6 m. Paired rows
planting pattern was adopted. Head loss calculation was made using William –
Hazan empirical equation. The tomato is one of the most popular and important
commercially grown vegetable. It has demand throughout the year. It is liked in
one or other form and therefore, it has become popular vegetable both among the
growers and consumers. Sprouting broccoli is an important cruciferous winter
season rare vegetable. Now a day in India, the popularity of broccoli is an
increasing trend in star categories and heritage hotels among affluent society
due to its nutritional superiority, however, its cultivation is negligible.
Owing to promotion of tourism, the scope of broccoli is very bright. Daily soil
moisture content of
root zone was monitored by AIC tensiometer for growth period of 4 months
(October to January).

The field experiments were conducted on different aspects
having level ground and 0.5 % up slope. The effects of various independent
parameters on different aspects for tomato and broccoli, such as vegetative
growth parameters, crop water requirements, water use efficiency, and cost
economics were evaluated.

Treatments combinations were as under

T1:
Broccoli grown on level ground with medi-emitters

T2:
Tomato grown on 0.5 % up slope with medi-emitters

T3:
Tomato grown on level ground with microtubes

T4:
Broccoli grown on 0.5 % up slope with microtubes

System was operated under 6 m pressure head, discharge of
emitters and its hydraulic parameters were evaluated and application time was
calculated on the basis of Kc and pan evaporation. Irrigation was scheduled
daily.

The experiment was laid out with four treatments, which were
treated as twenty-one replication (without treatment) for randomized block
design (RBD). Each subplot was comprised of 21 numbers of rows with 566 numbers
of plants, out of which 5 plants were selected randomly as observational
plants. Field layout of KB pressure treadle pump for one treatment is shown in
Fig. 1 and overall view of experimental site is shown in Plate No. 1.

The economy of a particular crop was assessed through
analysis of detailed cost and economic return. The cost includes total cost,
variable cost, fixed cost and cost per hectare of the output produced. The net economic
return includes income obtained from produce. Finally, the benefit-cost ratio
analysis was performed to judge the economic feasibility of LPLC drip
irrigation system. The economic analysis was conducted per hectare of
cultivated area under test crop.

Effective rainfall was determined using dependable rain methodology developed by FAO4. Estimating dependable rainfall, the combined effect of dependable rainfall (80 % probability of exceedance) and estimated losses due to runoff and percolation were considered. Following formula was used for calculation of effective rainfall .

Peff = 0.6 Ptot – 10 for Ptot<70 mm ….1

Where,

Peff = monthly effective rainfall, mm

Ptot = monthly total rainfall, mm

Daily
soil moisture measured before irrigation at 30 cm and 60 cm depth of soil
profile using AIC tensiometer. 10 cbar represents the field capacity of soil.
Fitted equation is given below

% moisture content = 39.57(cbar)^0.2398 …. 2

Design of Low Pressure Low Cost (LPLC) Drip Irrigation System

The system was designed on the basis of climatologically
data, constructed with locally available materials and components available at
IDEI, Ahmedabad. The William-Hazen formula was used for calculation of head
loss.

Pan
evaporation method was used for estimating crop water requirement5.

Volume of water required

V= (CA * PE *Pc *Kc*PWA )/Eu ………… 3

where, V= Volume of water required ,

CA= Crop area (m2)

PE= maximum pan evaporation (mm/day)

Pc= pan coefficient

Kc= crop coefficient

PWA= Percentage wetted area, (%)

Eu= emission uniformity, decimal.

Measurements of soil water content

Soil water content,
vegetative growth parameters, crop water requirements, water use efficiency,
and economic profitability were used to evaluate the overall performance of
each treatment. Soil water content (SWC) measurements were taken throughout the
experiment at 30 cm and 60 cm depth of soil profile using AIC tensiometer
before irrigation. Gravimetric method
was used for calibration of tensiometer. Soil-water retention curve was
prepared from different soil samples having different tensiometer readings.

drip irrigation system

Vegetative growth parameters
included four biometric parameters, above ground biomass (AG biomass), fruit
mass (FM), crop residue (CR), and root mass (RM) were measured at the time of
harvest. The fresh and dry weight of each aforementioned biometric parameter
was measured.

The Water use efficiency (WUE) is one of the best tools for the evaluating the performance of
different irrigation treatments. WUE was calculated as the ratio of the
crop yield (t/ha) to the total seasonal irrigation water applied (cm) during
the field growing season.

The economic viability of each irrigation treatments
was calculated considering each treatment was operated on a 156.25 m2
(566 plants). The total amount of fruit mass produce was determined by average
yield of randomly selected 5 plants within the plot and price based on market
rate.

RESULTS AND DISCUSSION

The study was conducted to find the economical feasibility of LPLC drip irrigation system.

Design of Low Pressure Low
Cost (LPLC) Drip Irrigation System

The
detail of various design and performance parameters for 6 m head are shown in
Table 1.

Quantity of irrigation water
applied depends upon crop coefficient (KC), pan coefficient (KP),
daily pan evaporation, per cent wetted area, crop area and uniformity of
system. Irrigation application time depends upon crop water requirement and
discharge of emitters. Daily application time under 6 m operating head was in
the range of 0.14 h (2.11 l/h) to 0.85 h (0.86 l/h). Lower application time
(0.14 h) was during initial crop phase and at low temperature with high
discharge emitters (medi-emitters) when crop water requirement was less where
as large application time (0.85 h) was applied during crop development phase
with high temperature and low discharge emitters (microtubes).

Ground water table

It is revealed from Table 2 that
total depths of applied water through out the growing season were 174.25,
170.19, 159.44 and 184.04 mm in treatments T1, T2, T3 and T4 respectively. Out
of the total 61 mm rainfall occurred during crop growing period, only 26.60 mm
was found to be effective. Monthly effective rainfall proportionate in days
based on proportion of rainfall received during the days (2 days rainfall
received in October).

Table 2 Seasonal water
requirement and consumptive use

Treatments

Total RainfallReceivedduringCrop Period,mm

Seasonal Water Requirement,
mm

ConsumptiveUse (CU)mm

IrrigationWaterApplied,mm

EffectiveRainfall,mm

Totalmm

T1

61.00

174.25

26.00

200.85

200.85

T2

61.00

170.19

26.00

196.79

196.79

T3

61.00

159.44

26.00

186.04

186.04

T4

61.00

184.04

26.00

210.64

210.64

Moisture
Content

Soil water content at field capacity was found to be 22.78 %. Daily drip irrigation maintained soil moisture near field capacity in 30 cm and 60 cm depth of soil profile. In general, 20 per cent soil moisture content was observed at both depths compared to 22.78 per cent field capacity. In case of medi-emitters, moisture content was low where as in case of microtubes, it was high. Soil moisture content at 60 cm depth was more than that at 30 cm depth of soil profile throughout the crop growing period. This might be due to less evaporation from the inner depth of soil profile. It was also observed that moisture content during rainfall (7 and 17, October) was above the field capacity other wise it was near or below it through out the crop growing period at 30 and 60 cm depth of soil profile in all treatments.

Vegetative Growth Parameters of drip irrigation system

The details of biometric parameters for all
the treatments are presented in Table 3. Treatments T1 and T3 performed
better than T2 and T4 with respect to vegetative growth parameters. From the
data of growth attributes (plant height, number of leaves, stem girth, ground
coverage, number of fruits, number of branch/secondary head, leaf area, leaf
area index, root growth, yield and quality of fruits, wet and dry matter
content) it is concluded that the treatments T1 and T3, performed better than
T2 and T4. The mean yield of fruit kg/plant of broccoli and tomato in treatment
T1 (1.01 kg) was higher than that in T4 (0.60 kg) and T3 (2.19 kg) followed by
T2 (1.93 kg) respectively. Yield of fruit (per ha) of broccoli and tomato in
treatment T1 (29.27 t/ha) followed by T4 (17.33 t/ha) and T3 (63.46 t/ha)
followed by T2 (56.03 t/ha) respectively.
Ultimately, farmers are most concerned with fruit mass produced as this
determines food production and/or cash income. Fruit mass had significant
variation in case of treatments T2 and T3 where as insignificant in case of T1
and T4 (p ≤ 0.05). The vegetative growth parameters were high and
superior quality in treatments T1 and T3 compared to T4 and T2. Yield of
broccoli and tomato under different treatments are shown in Fig.2.

Similar,
higher yield of tomato (67.3 t/ha) was reported for drip microtubes10
and 18.74 t/ha has been reported8. The yields
of broccoli was reported11 to be 11.11
t/ha.

The water use efficiency (WUE) is one of the best tools for evaluating the performance of different irrigation treatments. The WUE was calculated as the ratio of the crop yield (t/ha) to the total applied seasonal irrigation water (cm) during the crop growing season.

The WUE
for each treatment combination is presented in Table 4. The seasonal water
requirement was found to be 20.08, 19.68, 18.61 and 21.06 cm respectively for
treatments T1, T2, T3 and T4 and corresponding WUE are 1.46, 2.85, 3.41 and
0.82 t/ha-cm. The overall efficiency of water use in the experiment was found
to be high due to saving of water. Only a small portion of the area was
irrigated by controlled amount of water and deep percolation and the
evaporation losses were minimum. High efficiency of water use is extremely
important for farmers in water scarce semi-arid areas. The WUE of tomato
reported8 was 0.68 t/ha-cm for drip treatment. It was reported12 that WUE
ranging from 18.7-6.52 kg/ha-mm for sprouting broccoli.

Table 4 Seasonal water requirement, water use efficiency of
tomato and broccoli

Treatments

Average
Yield, t/ha

Seasonal
Water Requirement, cm

Water Use
Efficiency, t/ha-cm

Tomato

Broccoli

Tomato

Broccoli

Tomato

Broccoli

T1

–

29.27

–

20.08

1.46

T2

56.03

–

19.68

–

2.85

–

T3

63.46

–

18.61

–

3.41

–

T4

–

17.33

–

21.06

–

0.82

Economics

Drip irrigation is suitable for vegetables and orchards but it gives maximum return for vegetables within a season. Cost is the major constraint in adoption of drip irrigation for small land holders. The economic analysis was done as per existing market situation and the data pertaining to each component, cost of production of broccoli and tomato, net return from different irrigation treatments. As the cost of materials fluctuates very fast, the economic analysis may change with time and place. The price of the product may also vary from place to place and from time to time which will affect the economic analysis significantly. The generalized form of economic analysis data are given in Table 5 for different treatments. In analysis of economics of systems 70 per cent subsidy was also considered13.

Seasonal
cost of component per hectare without and with 70 % subsidy was in T1 (Rs. 168149/ Rs. 50445) and T2 (Rs.168149/ Rs.
50445) followed by T3 (Rs. 46249/ Rs. 13875) and T4 (Rs. 46249/ Rs.13875)
respectively. Seasonal cost of cultivation per hectare was in T2 (Rs. 54343)
and T3 (Rs. 54343) followed by T1 (Rs. 51784) and T4 (Rs. 51784). Seasonal
return from produce per hectare was in T3 (Rs. 634600) followed by T1 (Rs.
585380), T2 (Rs. 560342) and T4 (Rs. 346591) respectively. Net seasonal income
without and with subsidy (70 %) per hectare was in T3 (Rs. 534008/ Rs. 566383)
followed by T1 (Rs. 365447/ Rs. 483151), T2 (Rs. 337850/ Rs. 455554) and T4
(Rs. 248558/ Rs. 280933) respectively. The developed system has pay back period
of one season only, benefit to cost (B/C) ratio varies from 1.52 to 5.31
without subsidy and 4.28 to 8.30 with subsidy.

Table 5 Benefit cost ratio of broccoli and tomato under different irrigation treatments in drip irrigation system

S. No.

Cost economics

LPLC
drip irrigation system

Broccoli

Tomato

Medi-emitters
(T1)

Microtubes
(T4)

Medi-emitters
(T2)

Microtubes
(T3)

Without
subsidy

With
70 % subsidy

Without
subsidy

With
70 % subsidy

Without
subsidy

With
70 % subsidy

Without
subsidy

With
70 % subsidy

1

Fixed cost

146217.0

43865.0

40217.0

12065.0

146217.0

43865.0

40217.0

12065.0

a

Depreciation

13160.0

3948.0

3620.0

1086.0

13160.0

3948.0

3620.0

1086.0

b

Interest

7311.0

2193.0

2011.0

603.0

7311.0

2193.0

2011.0

603.0

c

Repair and
maintenance

1462.0

439.0

402.0

121.0

1462.0

439.0

402.0

121.0

d

Total (1+a+b+c)

168149.0

50445.0

46249.0

13875.0

168149.0

50445.0

46249.0

13875.0

2

Cost of cultivation

51784.0

51784.0

51784.0

51784.0

54343.0

54343.0

54343.0

54343.0

3

Seasonal total cost
(1d+2), Rs

219933.0

102229.0

98033.0

65659.0

222492.0

104787.0

100592.0

68217.0

4

Yield of produce, t/ha

29.27

29.27

17.33

17.33

56.03

56.03

63.46

63.46

5

Selling price, Rs/kg

20.00

20.00

20.00

20.00

10.00

10.00

10.00

10.00

6

Income from produce,
(4×5), Rs

585380.0

585380.0

346591.0

346591.0

560342.0

560342.0

634600.0

634600.0

7

Net seasonal income,
(6-3), Rs

365447.0

483151.0

248558.0

280933.0

337850.0

455554.0

534008.0

566383.0

8

Seasonal BC ratio,
(7/3)

1.66

4.73

2.54

4.28

1.52

4.35

5.31

8.30

Life of components = 5
years, Season considered = 2, Interest rate = 10 %,

Repair and maintenance cost
= 2 % of total cost.

Since the payback period for all treatments is 1 season and B/C ratio
is more than 1, even as high as 5.31 (without subsidy) in case of microtubes,
this may be considered to be a viable option for small landholders.

It was reported10 that B/C ratio, 9.81 for drip microtubes
in case of high yield tomato. The net return of Rs. 88601/ha with B/C ratio
3.99 from sprouting broccoli was reported11. Several researchers
reported higher crop yield and more income from the produce besides saving of
water through drip methods of irrigation14, 15, 16, 17 and 18.

It was reported1 that installation cost of micro-drip irrigation was Rs.78000/ha with B/C ratio 6.36 where as Rs. 100000/ha for lateral spacing of 1.8 m with cost of cultivation Rs. 67214 with B/C ratio 3.81 has been reported.

drip irrigation system

CONCLUSION FOR DRIP IRRIGATION SYSTEM (LPLC)

Treatments T1 and T3 performed better than T2 and T4 with respect to vegetative growth parameters. Microtubes performed better than medi-emitters. Daily drip irrigation maintained soil moisture near field capacity. As the payback period for all treatments is one season and benefit to cost (B/C) ratio is in the range of 1.52 to 5.31 without subsidy and 4.28 to 8.30 with subsidy, it can be presented an attractive prospect. Water efficient irrigation method (LPLC) drip irrigation system that is affordable, divisible and appropriate can significantly improve food production and the livelihoods in water scarce areas of developing countries, promoting greater economic and food security.